Valve arrangement for pneumatic dispatch tube systems



July 19, 1960 Filed March 17, 1959 J. MULLER VALVE ARRANGEMENT FOR PNEUMATIC DISPATCH TUBE SYSTEMS 2 Sheets-Sheet l Fig. 1 a

Fig. 2

Fig. 1b

INYENTOR. J MULLER A am WWW

July 19, 1960 J. MULLER VALVE ARRANGEMENT FOR PNEUMATIC DISPATCH TUBE SYSTEMS Filed March 17, 1959 2 Sheets-Sheet 2 ll I [i Fig 3b INVENTOR.

VALVE ARRANGEMENT FOR PNEUMATIC DISPATCH TUBE SYSTEMS Joachim Miiller, Berlin, Germany, assignor to International Standard Electric Corporation, New York, N.Y., a corporation of Delaware Filed Mar. 17, 1959, Ser. No. 799,945

Claims priority, application Germany Mar. 27, 1958 3 Claims. (Cl. 243-22) The invention relates to pneumatic tube dispatch systems and more particularly to improvements in valves that serve to separate from each other two spaces filled with gases at different pressures and which can be opened by a relatively small force considering the pressure difference. The invention provides a valve which is simply constructed, quiet in operation and the force necessary to operate it is efiective substantially in a straight line or in an arc, as preferred.

Valves are particularly necessary in dispatch tube systems in order to balance the pressure differences between two tube systems and in particular to enable the passagethrough between said system of dispatch carriers. A special importance is attached to such valves where they serve to eject carriers from the dispatch tubes.

Flap valves have previously been employed in which either a part of the flap or a separate valve are actuated just before opening the main valve, the arrangement being such that any pressure difierence shall, at least in part, be reduced either with the aid of the flaps opened a little or by means of the separate valve. Thereby the pressure owing to which the flap bears against the valve seat will be lessened so that the flap can be opened with a small force.

In this respect flaps have become known that are of different stifiness at their various points. For example, the stiffness along a buckling line of the flap may differ from the stiffness of the other flap parts. Also, the flap may have stiffening ribs owing to which its external face is corrugated.

It has been found, however, that when a valve, according to arrangements such as these, is required to be opened, it requires a relatively large force to be employed for this purpose and that its operation is still somewhat noisy.

In order to avoid these drawbacks, or at least to lessen them, the invention uses a flap valve whose flap is a sort of tape of a pliable material and is, on the high pressure side, fixed with one end to a point near the edge of the valve aperture, provided in a plate. The other end of the flap is so attached to a lever or similar means that in consequence of this lever or means being moved, the flap shall be either rolled down on the valve aperture or rolled away from it.

The above-mentioned and other features and objects of the invention and the manner of attaining them will become more apparent and the invention itself will be best understood by reference to the following description of an embodiment of the invention taken in conjunction with the accompanying drawings in which:

Fig. 1a illustrates the principle of the valve according to the invention, and shows the valve in the closed position;

Fig. lb shows the valve of Fig. 1a in an open position;

Fig. 2 shows a side elevation of the inventive valve used in a pneumatic tube dispatch system;

Fig. 3a is a front elevation partly in section of a valve ice operated by a lever moving parallel to the valve apertures and constitutes another embodiment of the invention; and Fig. 3b is a plan view of the valve shown in Fig. 3a. Referring now to the drawing, the inventive valve is shown as a plate 1 in which the valve aperture 2 is provided. This aperture can be closed by a tape 3 made of a pliable elastic material. Tape 3 is fixed to plate 1, and on one side of aperture 2, by means of screws 3a. In order to open the valve, the tape 3 is seized at its free end and pulled toward the said fastening screws so as to uncover the aperture 2, as will be understood from Fig. 1b. Since the tape 3 is effectively peeled away from aperture 2, the force necessary to move the tape is relatively small. I

Fig. 2 discloses a practical arrangement of the valve whose principle is shown in Figs. 1a and lb. In this figure there is shown, partly in section, a pneumatic tube system and consisting of the tube 4 maintained at high pressure and a tube 6 maintained at a somewhat lower pressure. Pneumatic'tube dispatch carriers (not shown) are adapted to be carried within the tube 4 in a direction toward the tube 6. The tubes 4 and 6 are joined by an airtight housing 4a, shown in section, and which housing is fastened to said tubes at points 4b and 6a, respectively. The housing 4a thus defines a chamber generally indicated at 40. The end of the tube 6 within the chamber 4c is diagonally shaped, as shown. The flap 5 is adapted .to have one end 5a attached to the outer surface of the tube 6 at the lowermost portion of the diagonal. The free end of the flap 5 is attached at 5b to a generally triangular shape lever 7 adjacent an angle thereof. The lever 7 is rotatably mounted adjacent another angle thereof from a fixed pivot 7a, which pivot extends between walls of the housing 4a. The side 7b of the lever 7 extends through the tube 4 in the aperture 4d. It will thus be seen that the side 7b of the lever will be directly in the path of an arriving dispatch carrier,

which is moving toward the direction of the tube 6. The

dispatch carrier will tend to urge the lever 7 in a clockwise direction around the pivot 7a, as indicated by the dotted lines, and as a result of which pivoting the flap 5 will be peeled away from the orifice of the tube 6, as shown. In this manner a carrier leaving the high pressure tube 4 may enter the low pressure tube 6 and immediately the flap 5 will return to its closed position due to the fact that it is made of pliable elastic material. If desired, the lever 7 may be spring urged by a resilient element (not shown) to remain in the normally closed position, as shown in the drawing.

In order to prevent the pressure differential between the tubes from deforming the flap 5, I provide transverse ribs 5c, as shown in the drawing, which stiffen the flap. These ribs are transverse to the direction of motion of the flap as it is opened. These ribs may be embedded in the elastic material of the flap or may be attached thereto in any other suitable manner. that the lever 7 is caused to move in a plane vertical to the plane of the aperture of tube 6. Lever 7 is so proportioned that it may be rotated, as explained previously, by an arriving carrier before the carrier reaches the diagonal plane of the orifice of the tube 6.

Fig. 3 is a sketch, partly in section, of a modification of the invention wherein a valve flap 8 is movable by means of a bell crank lever 8a. In this embodiment the flap 8 is again made of pliable material and is adapted to cover the apertures 9. Bell crank 8a is pivoted to rotate about the fixed pivot 8b. Upon counterclockwise movement of the bell crank 8a, the flap 8 will be pulled away from the apertures 9. In the arrangement shown in Figs. 3a and 3b, it is unnecessary to utilize strengthening ribs across the flap by reason of the fact that the It will be noted.

apertures .9 have material separating them and whichrsupport'the flap. The 'structure'in Figs. 3a and 3b may be used "for 'anytype-of valve and is not necessarily "limited to a pneumatic tube dispatch device. The structure in Figs. 3a and 3b afiords a device wherein very little force is required to actuate'thevalve. To increase the pliability of the -fiap"8, the cross-sectional area thereof adjacent 'the fastened portion 9a is reduced andis indicated as 9b.

While -Ihave described above theprinciPles of -my invention in connection'with specific apparatus, it is to-be clearly understood that this description is made onlyby way of example and not as a-limitation to the scope of my invention, "as set forth in the objects thereof and in the accompanying claims.

What is claimed is:

1. In amulti-pressurepneumatic tube 'system, the combination of a pair of tubes operating at diiferent pressures, an airtight housing coupiingthe 'ends of said'tubes, a triangular-shaped lever pivotally mounted adjacent an angle thereofto saidhousing-on an axisnormal to the longitudinal axes of said tubes, a J-shaped valve fiap extending 'over theendo'f the first tube of said pair and which tube is operated at the lowesto'f said pressures, said flap being made of pliable material, the=straight end of said flap being 'fastened -to said first tube and the 25 outer surface of the J-"shaped end of said flap being fastened adjacent another angle of said lever, the side of said lever opposite said last mentioned angle extending into the-other tube of said-pair and which tube is operated at the highest of said pressures and being within the path of a dispatch carrier moving therein in a direction toward said other tube, said lever adapted to be actuated by such a carrier and to pivot out :of the path of said carrier wherebysaid "valve flap is .rolled awaytrom the end of said first tube rto allowcommunicationbetween said tube pair and entry of said'carrier into said first tube.

"2. In a pneumatic'tube system, as claimed in claim 1, whereinsaid valve flap comprises a -plurality of spaced, stiffening elements extending in a direction normal to the direction ofmovement of .said flap.

3. In a pneumatic tube system, as claimed in claim 1, further comprising resilient means' to normally urge said lever into said other tube whereby to maintain said valve flap across the end of said 'first tube.

:FOREIGN PATENTS Germany Nov. 26, 1934 

